I. Field of the Invention
This invention pertains to systems for providing therapeutic fluids to selected sites in a patient's body. More particularly, this invention relates to a device for supporting a needle transferring fluids to a subcutaneous drug administering device.
II. Description of the Prior Art
The art of drug administration is known to include fluid receptacles which are implanted beneath the skin of a patient. From time to time, these receptacles are filled by hypodermic injection with a multidose quantity of a drug which is delivered to a site in the patient's body. The drug is delivered from the receptacle by a catheter which is also surgically implanted beneath the skin. Alternatively, the drug can be administered via a drug-permeable membrane. Such devices include implantable pumps which are located by palpitation and are mechanically pumped to administer the drug. Also included are diaphragms with catheters implanted beneath the skin.
Implantable fluid reservoirs have several advantages in treating a patient. One advantage is the reservoir can be used without the need for a catheter extending through an incision in the patient's skin for administering a fluid to a desired site. The fluid reservoir is filled from time to time by use of a transcutaneous conduit such as a hollow needle which is inserted through the skin into the reservoir. Such reservoirs are provided with walls which are puncturable by needles but reseal upon withdrawal of the needle. A needle currently approved for use with such receptacles is the well-known Huber needle which, due to the configuration of the needle tip, minimizes damage to the self-sealing membrane of the reservoir.
A current problem associated with transcutaneous transfers of fluid through a needle into a subcutaneous drug reservoir is the prior art has not found an adequate way to support the needle during injection. Such injections may last a matter of minutes or a matter of hours. In any event, the needle must remain secured to the patient to ensure the needle is not accidentally removed from the drug reservoir. Historically, a person administering the drug must tape the needle to the patient's body by improvising an anchor formed of adhesive tape. However, such an approach is not always effective and is frequently time consuming and cumbersome. A prior art apparatus which addresses this problem and attempts to provide a solution is U.S. Pat. No. 4,464,178 to Dalton dated Aug. 7, 1984. Dalton teaches an anchor for a transcutaneous fluid delivery conduit such as a hypodermic needle. The anchor comprises a protective boot which includes a plurality of concentric annular rings having inside and outside peripheries. The rings are stacked using the needle as an axis. The stacked rings provide shock absorbing extension and compression along the needle axis. The apparatus of Dalton remains in place between drug administrations. Therefore, the apparatus of Dalton provides means for reducing the number of required injections through a patient's skin. However, the apparatus of Dalton does not appear to be a practical anchor for use of an occasional injection into a reservoir where the presence of an anchor is not desired on a continuous basis. In such cases, the apparatus of Dalton would be a cumbersome apparatus to use to support a needle during transcutaneous injection.